eARC problems with LG CX (Beam and Arc)

  • 19 December 2020
  • 28 replies

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QuiXilver do you have a Sonos ARC connected to your LG CX?  Are you having problems with it?

QuiXilver do you have a Sonos ARC connected to your LG CX?  Are you having problems with it?

Yeah I just bought the Sonos Arc a few weeks ago (my first Sonos product). And yes, it is connected to my CX via hdmi arc. I enabled eARC on the tv and set the digital sound out to Pass through. I've had minor issues:

  • Netflix on the tv app sometimes stops outputting sound but it's only happened between episodes as opposed to randomly while an episode is playing. It appears the Sonos loses the hdmi arc signal. If I change the source to internal then back to hdmi arc it solves it. Or a reboot of the tv also helps.
  • The same happened to my Xbox Series X once and if I remember correctly the same solution helped
  • More confusing is my PS5. Sound stopped all of a sudden after me not changing a thing. I had to set the sound format from lpcm to dolby for it to work. But a better solution to keep lpcm was to set the hdmi audio in on the tv to pcm from Bitstream. 

But mine are minute compared to yours. I had a similar issue with a samsung hw-k950 soundbar some years ago. Rears and sub would disconnect from the main bar. I think mine was interference though hence my suggestion of wiring your setup.


I know it's a long shot but if you don't get answers from Sonos here, try reaching out to a youtuber Peter Pee or Jonah Mathes. They've done some great reviews on Sonos products. Peter’s is very in depth and I feel if anyone can help, it'll be him. I really hope you come right.

I made a mistake in my last post, the ARC does discount from the SUB and ONE SL’s when the TV is turned on and it’s using the optical port.  It just needs to set overnight with the TV off and when the TV is turned on it disconnects from the SUB and ONE SL’s.  The ARC continues to work otherwise and when the TV is turned off it reconnects to the SUB and ONE SL’s.  I can also get it to reconnect by power cycling all the SONOS components.  I’m using the IOS Sonos APP to monitor the ARC.  I’ve tried wired and wireless modes, it’s not an RF interference problem because I can get the system working by cycling power on all the SONOS components after the TV is on. Once it’s working it stays up until the TV is turned off for a couple hours and then turned back on.  Everything is pointing to a firmware bug in the SONOS components.

Is there a way to back up the firmware version on the SONOS components?


I meant to ask you - have you tried removing the sub from your setup and leaving the sl’s and arc connected? Then connect the sub and remove the sl’s. Does it behave the same in these scenarios? I'm wondering if one of them are causing the issue.